Transcript Student Module_5

Major Minerals
in Bone and
Protein
Module 5.4
Minerals in the Body
Minerals: small, naturally occurring, inorganic (other than
plant/animal), chemical elements naturally found in earth.
– Minerals are available in unprocessed foods, some
processed foods and dietary supplements
• Major mineral: an essential mineral nutrient found in the
human body in amounts greater than 5 grams.
• Trace mineral: an essential mineral nutrient found in the
human body in amounts less than 5 grams.
• Major minerals = electrolytes (sodium, potassium, and
chloride)
• Major minerals in bone = calcium, phosphorus, and
magnesium
• Major mineral in protein = sulfur
• Trace minerals = iron, copper, iodine, manganese, fluoride,
chromium, molybdenum, selenium, zinc, & cobalt
Calcium
Most abundant mineral
Bones store 99% of the body’s calcium; 1% in body fluid
 PTH and Calcitonin affect blood calcium levels
 Absorption enhancer
 Vitamin D dependent, fat, lactose, acidic foods
 Osteoporosis and osteopenia caused by deficiency of calcium
 Absorption inhibition
 phytic acid (phytate- whole grains, seeds);Oxalic acid
(spinach, sweet potatoes); Fiber; High protein intake affects
excretion of Ca; tannins (teas)
 Phytates and oxalic acid bind to calcium and form insoluble
salt complexes, thus decreasing calcium absorption
Functions:
–
Bones – Remodeling: resorption/deposit; Tooth enamel
–
Nerve impulses; Muscle contraction- Heartbeat
–
Maintenance of blood pressure
–
Blood clotting
Calcium (Ca) Deficiency & Toxicity & Sources
Deficiency
(<66% of DRI)
Approx. <660790 mg/day
Adequacy
DRI:
1,0001,200
mg/day
RDI: 1000
mg
Toxicity
(>UL)
>2,500
mg/day
Osteopenia
Bone & tooth:
stunted growth
in children, low
bone density,
osteoporosis
Normal
Bone and
tooth
structure,
muscle
contraction
, nerve
conduction
, blood
clotting
Hypercalcemi
a
GI System:
constipation,
reduces
absorption of
iron,
magnesium,
zinc, and
phosphorus.
Other: kidney
stones,
calcium
deposits in
soft tissues
• Diary product sources: milk, yogurt, &
cheese and foods made with diary
products like pudding. Cow’s milk
has good bioavailability of calcium
(about 30 to 35%). It is estimated that
without milk and milk products in
the diet, less than ½ of the calcium
requirements would be met
• Non dairy sources include fortified
foods like soymilk and cereal, canned
fish with the bones, spinach, turnip
greens, tofu, broccoli, and kidney
beans.
– The bioavailability of Ca is one of
the highest (~50%) from
cruciferous vegetablescauliflower, cabbage, broccoli
– 125 ml-1/2 cup broccoli = 35 mg
Ca of which 22mg is absorbable
(61%); would need to have 4.5
servings of broccoli to equal
one cup of milk
Calcium in Dairy Foods
~ 30% bioavailability
Chocolate Pudding (1 c)
Cheddar Cheese (1 oz)
Swiss Cheese (1 oz)
Lowfat Vanilla Yogurt (1 c)
1% Milk (1 c)
Whole Milk (1 c)
276
205
221
419
264
246
0
50
Kidney Beans (1 c)
100
150
200
250
300
350
400
450
35
Blackstrap Molasses (1 T)
172
Cooked Broccoli (1 c)
62
Cooked Spinach (1 c)
244
Canned Salmon (1 oz)
Calcium in Non Dairy
Foods
<5 to >50% bioavailability
60
Fortified Tofu (1 c)
94
Fortified Soymilk (1 c)
300
Fortified Cereal (1 c)
1333
0
DRI: 1,000-1,200 mg/day
Calcium (mg)
200
400
Calcium (m g)
600
800
1000 1200 1400
Calcium Supplements
• Calcium carbonate. Better
absorbed when taken with food.
– 40% Calcium
– 500 mg tablet provides 300 mg
Carbonate & fillers
– 200 mg Calcium
• Calcium citrate. Can be taken on
an empty stomach.
– 21% Calcium
– 500 mg tablet provides 394 mg
Citrate & fillers
– 105 mg Calcium
• Avoid:
– Oyster shell, coral, bone meal, calcium phosphate, anti-acids
supplements due to poor absorption, non-optimal design,
and/or possible contamination.
Phosphorus –2nd highest mineral
• Bone formation-stored 85% in bones and
teeth; accounts for about 1% of an adult body
Functions
• Combined with calcium to form calcium
phosphate; rigidity to bones and teeth.
More readily absorbable than calcium
• Part of nucleic acids (DNA and RNA); necessary for
all growth; genetic code.
• Plays major role in energy production (creatine
phosphate and ATP)
• Important in pH regulation –removal of H+ ions
• Element of phospholipids
• Component of enzymes and hormones
• High levels suppress Vitamin D conversion reducing
Ca levels in the blood
• Sources: Available in most foods
– best source: animal products; carbonated drinks
Phosphorus (P)
Deficiency & Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
Approx. <460 mg/day
DRI: 700 mg/day
RDI: 1,000 mg
(>UL)
>4,000 mg/day
Hypophosphatemia
Bone & tooth: bone
pain
GI System: anorexia
Neuro-Musccular:
muscle weakness
Other: general debility
Normal bone & tooth
structure, DNA, ATP,
phospholipids,
phosphorylation
reactions, and
buffering systems.
Hyperphosphatemia
GI System: reduced
calcium absorption
Other: calcification of
non-skeletal tissues.
The body strives for a calcium to
phosphorus ratio in the blood
stream of 1:1
Adult deficient, adequate, toxic values
Phosphorus in Foods
• Animal products
• Processed foods
• Preserved foods
Adult DRI: 700 mg/day
Magnesium
• 50% stored in bones- acts as bone reservoir-50% musclestissues; 1% in the blood
• Most of the remaining magnesium inside cells
• Deficiency can result in sudden death due to heart failure also
cause of osteoporosis; alcoholism associated with deficiency
• Absorption enhanced by Vit D; inhibited by calcium or phytates
Functions
• Stabilizes ATP molecule- needed for every reaction that
synthesizes ATP and DNA.
• Helps RELAX muscles by blocking calcium actions. Inadequate
amounts of dietary Mg can lead to muscle cramps and spasms
• Important in converting blood sugar into energy
• Regulates blood pressure
• Affects calcium homeostasis
• Suppresses PTH(breakdown of Ca2+); stimulates calcitonin
• Glycolysis energy pathway requires Mg in seven (7) enzymatic
reactions. Magnesium is a cofactor for over 300 enzymes
Magnesium (Mg)
Deficiency & Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
Approx. <205-280 mg/day
DRI: 310-420 mg/day
RDI: 400 mg
(>UL from supplements)
>350 mg/day
Rare in healthy people.
Associated with
hypocalcemia
Central Nervous
System: seizures
Neuro-Musccular:
muscle cramping,
hyperexcitability
Other: vitamin D
metabolism
interference
Normal bone,
tooth, and
protein building;
enzyme action,
muscle
contraction,
blood clotting,
and nerve
impulse
transmission
From supplements and
laxatives
GI System:
diarrhea, nausea,
abdominal cramps,
paralytic ileus
Other: metabolic
alkalosis,
hypokalemia
Adult deficient, adequate, toxic values
Magnesium in Foods
• Mostly plant foods: almonds, cashews legumes, whole grains,
dark green leafy vegetables, halibut, chocolate, and cocoa.
• ~80% lost in grain processing.
• Is not added back to processed foods
Adult DRI: 310-420 mg/day
Osteoporosis
the silent bone stalker
Risk Factors
• High Protein & Phosphorus intake
• Low calcium, vitamin D, magnesium, and fluoride intake
• Genetics (family history, small frame size)
• Lack of Exercise
TYPE 1
TYPE 2
• Very high fiber intake –
reduces calcium absorption
• Smoking & Alcoholreduces calcium absorption
• Menopause – decrease
estrogen
Postmenopausal
Senile
Onset age
50-70 years
>70 years
Bone loss
Trabecular
Trabecular &
cortical
Gender
Women:Men
6:1
Women:Men
2:1
Fracture
site
Wrist & Spine
Hip
Cause
Estrogen loss
following
menopause in
women.
Testosterone loss
with age in men.
Reduced calcium
absorption,
increased
demineralization of
bone, increased
propensity to fall.
Bone
Trabecular Bone:
– The lacy inner structure of calcium crystals
that supports the bone’s structure &
provides a calcium storage bank.
Cortical Bone:
– The very dense bone tissue that forms the
outer shell surrounding trabecular bone
and comprises the shaft of a long bone.
Types of Fractures
• Wrists (least severe) Most occur at age 50 or older
– early warning sign for osteoporosis.
• Spinal vertebrae (chronic back pain) More likely at 55-75 years
– Fractures occur from bending or lifting
– Several fractures leading to loss of height & spinal curvature
• Hips (most serious) Most occur at 70 years or older
– 20% die with in 4 months
– 50% become institutionalized
Bone Mass and Osteoporosis
• Bone mass gained up to~ 25 yrs.
• Bone mass stabilized up to~ 40 yrs.
• Bone mass is lost after ~50 yrs.
Sulfur
• Component of biotin, thiamin, amino acids
– methionine and cysteine =important for protein
structure --- disulfide bonds-assists proteins in maintaining
structural rigidity and integrity
– Keratin, present in the skin, hair, and nails, high in amino acid
cysteine. The sulfur-sulfur bond in keratin gives it greater strength
• Produces noxious odor in certain foods (cabbage, cauliflower,
garlic) and chemicals
• Cartilage - chondroitin sulfate
• Antibodies, hormones (insulin) anticoagulants (heparin); enzymes
• Structural component of serotonin-vasoconstrictor that aids in blood
clotting.
• Component in coenzyme A
• Used in medications for diabetes, gout, heart disease, Crohn's
disease, ulcerative colitis, inflammation, infection, and rheumatoid
arthritis
– EX: Lasix, Celebrex, migraine medication -Imitrex
• No recommended intake
Sulfur (S)
Deficiency & Toxicity & Sources
Deficiency
Not Established
Adequacy
DRI & RDI
Not
Established
Toxicity
UL is Not
Established
Sulfur has no
known
deficiency state.
Protein
deficiency
would appear
first.
Normal
biosynthesis
of sulfur and
sulfate
containing
compounds
GI System:
osmotic
diarrhea and
may
contribute to
inflammatory
bowel disease
such as
ulcerative
colitis
Sources:
• Dried fruit, commercial
breads, soy,
sausages, tap water,
some beverages
• Beans, poultry, eggs,
garlic, onion, cabbage,
cauliflower
• The major source of
sulfur is from cysteine
and methionine. Most
proteins have a
significant amount of
both of these amino
acids.